Description

# Bash
# Prerequisite: You will need to create the directory "/snapshot", allowSnapshot() on it, and create a snapshot named "snap3"for it to reach NPE.
$ curl "http://<SERVER>:<PORT>/webhdfs/v1/snaptest/?op=GETSNAPSHOTDIFF&user.name=hdfs&oldsnapshotnameZZZ=snap2&snapshotname=snap3"# Note that I intentionally typed the wrong parameter name for"oldsnapshotname" above to cause NPE.
{"RemoteException":{"exception":"NullPointerException","javaClassName":"java.lang.NullPointerException","message":null}}
# OR
$ curl "http://<SERVER>:<PORT>/webhdfs/v1/snaptest/?op=GETSNAPSHOTDIFF&user.name=hdfs&oldsnapshotname=&snapshotname=snap3"# Empty string for oldsnapshotname
{"RemoteException":{"exception":"NullPointerException","javaClassName":"java.lang.NullPointerException","message":null}}
# OR
$ curl "http://<SERVER>:<PORT>/webhdfs/v1/snaptest/?op=GETSNAPSHOTDIFF&user.name=hdfs&snapshotname=snap3"# Missing param oldsnapshotname, essentially the same as the first case.
{"RemoteException":{"exception":"NullPointerException","javaClassName":"java.lang.NullPointerException","message":null}